The Worlds are different game servers within a region. All worlds within a region share the same diamond account, so diamonds bought or won on one world of a region can be used by the same player account on all other worlds of the same region.
If a new player is joining the game via the global loading page, the players region is chosen based on their IP address and their first world is selected randomly. A player can chose to start to play on a different world at any time. When starting a new game, the player needs to choose a world to belong to. It is strictly prohibited to have more than one player account in the same world.
A player is further not limited to play in a specific region. The player must however create a new account for every region they want to play in. The same user name may be used in different regions.
All players are ranked to each other within a world.